class Runtime

final class Runtime {
    private readonly OperatingSystem $operatingSystem;
    private readonly PHP $php;
    private readonly PHPUnit $phpunit;
    public function __construct() {
        $this->operatingSystem = new OperatingSystem();
        $this->php = new PHP();
        $this->phpunit = new PHPUnit();
    }
    public function asString() : string {
        $php = $this->php();
        return sprintf('PHPUnit %s using PHP %s (%s) on %s', $this->phpunit()
            ->versionId(), $php->version(), $php->sapi(), $this->operatingSystem()
            ->operatingSystem());
    }
    public function operatingSystem() : OperatingSystem {
        return $this->operatingSystem;
    }
    public function php() : PHP {
        return $this->php;
    }
    public function phpunit() : PHPUnit {
        return $this->phpunit;
    }

}